The following cOS Core advanced settings are available for High Availability:

Sync Buffer Size

How much sync data, in Kbytes, to buffer while waiting for acknowledgments from the cluster peer.

Default: 4096

Sync Packet Max Burst

The maximum number of state sync packets cOS Core can send in a burst.

Default: 100

Initial Silence

The time in seconds to stay silent on startup or after reconfiguration. When the active unit in an HA cluster believes the inactive unit is no longer reachable, it continues to send synchronization traffic normally for a period of one minute in the expectation that the inactive unit will again become reachable. In order not to flood the network unnecessarily, after one minute has elapsed, the synchronization traffic is then only sent after repeated periods of silence. The length of the silence is taken from this setting.

Default: 5

Use Unique Shared Mac

Use a unique shared MAC address for each interface. For further explanation of this setting see Section 13.3.5, Unique Shared Mac Addresses.

Default: Enabled

Deactivate Before Reconf

If enabled, this setting will make an active node failover to the inactive node before a reconfigure takes place instead of relying on the inactive node detecting that the active node is not operating normally and then taking over on its own initiative. Enabling this setting shortens the time where no node is active during configuration deployments.

Default: Enabled

Reconf Failover Time

Number of non-responsive seconds before failover at HA reconfiguration. The default value of zero means immediate reconfiguration. This setting controls if unit should behave like a standalone unit by not changing the cluster nodes active/inactive state during deployments or reconfigure, depending on the value set.

Default: 0

HA Failover Time

Number of milliseconds that the active unit in the cluster has been unresponsive before a failover is initiated by the inactive unit.

Default: 750